ABSTRACT
The results of the study of the influence of a static magnetic field of 55 ± 3 mT on the growth rates of diamagnetic sodium chlorate crystals in the direction ⟨100⟩ will be presented. Two groups of experiments were performed in the same solution supersaturation range of 0.89-1.78%, the first in zero field conditions, and the second in an applied magnetic field. The results show that crystals nucleated and grown in a static magnetic field have higher mean growth rates in the ⟨100⟩ direction than crystals in a zero field. Also, X-ray analyses suggest that crystals nucleated and grown in a magnetic field may have a higher lattice constant. Possible mechanisms and possible reasons for these phenomena are discussed.
ABSTRACT
Dependence of growth rates of {100} sodium chlorate crystal faces on solution supersaturation in the range of 0.44-1.32% was analyzed. It has been shown that the growth rate dispersion does not have a consequence only in the growth parameter differences predicted by specific crystal growth theory but that individual crystal faces may grow with different mechanisms under the same experimental conditions. The majority of the observed {100} sodium chlorate crystal faces grew in accordance with the power law R â¼ σ n , whereas approximately one-third of them grew in accordance with BCF or Chernov's theories. Possible reasons for this as well as for the coexistence of crystal faces, which grew with different mechanisms under the same conditions, have been discussed.
ABSTRACT
Hemp fibers with different amount of hemicelluloses and lignin were subjected to atmospheric pressure dielectric barrier discharge under different conditions (40â¯W and 80â¯W power of discharge, const. time 120â¯s) in order to study influence of plasma treatment on their structure and sorption properties. Wettability of plasma treated samples, compared with precursors, increased due to the changes in hemp fiber surface chemistry confirmed by ATR FTIR spectroscopy and increased roughness as a consequence of intensive surface etching, observed by SEM. After plasma treatment, wettability was the highest for hemp fibers with lower content of hemicelluloses (increase up to 9 times), while wettability of raw hemp fibers and fibers with lower content of lignin increased about 5 and 2 times, respectively. This investigation shows that plasma can be successfully used for improvement of raw hemp fibers wettability, even to substitute the chemical treatment for some applications of hemp.
